Radio tube socket



May 1935. R. M. HEINTZ 205$3 RADIO TUBE SOCKET Filed May 1, 1933 INVENTOR. RALPH M. HE/NTZ.

WfW I ATTORNEY Patented May 7,. 1935 UNITED STATES! 4 PATENT OFFICE RADIO TUBE SOCKET Ralph Mnemtz, Palo Alto, cam. assignor to Heintz & Kaufman, Ltd., San Francisco, Caliifl, a. corporation of Nevada Application May 1,1933, Serial No. 668,779 2 Claims. (01. 173-328) ,10 vacuum tube socket in which the contacts will firmly grip the vacuum tube base pins; to provide a vacuum tube socket in which repeated insertions of a vacuum tube base will not weaken the grip of the socket receptacles; and to provide a vacuum tube socket which furnishes electrical connections to the pins of a vacuum tube base adequate to,

carry heavy currents. Other, objects of my invention will be apparent or will be specifically pointed out in the description'forming a part of this specification, but I do not limit myself to the embodimentof my invention, herein described, as various forms may be adopted within the scope of the claims. In the drawing which illustrates a typical socket embodying my invention: 7

Figure l is a top view in elevation.

1 Figure 2 is a sectional view, partly in elevation, taken along a plane indicated by the line 2-2 in Figure 1.

seen from below.

Figure 4 is a view in elevation of a contact strip. Figure 5 is a plan view, p artly in section taken as indicated by the line 5-5 in Figure 4. 35 Certain of the high power radio vacuum tubes,

. such'as the well known fifty watt type, are provided with a cylindrical base and four short contact pins. While the socket to be described is adaptable to be used with other types of tubes 40 having bases of the same general type, the particular embodiment here shown is made particularly to receive the base of the fifty watt tube. The dimensions of this base are standardized in the art, and a socket designed to fit the tubes of 45 one manufacturer will handle tubes of other manufacturers without adjustment.

The filament 1 of the fifty watt tube requires a heavy current for proper, operation, and the plate is often supplied with a potential of 3,000

50 volts or more, also with a relatively high current.

The tube is often used as a high frequency oscillation generator, thus creating high frequency al- "-temating current stresses in the socket. A socket,

therefore, to be satisfactory for use with such.

55 tubes, must have good electrical contact to the Figure 3 is a view in elevation of the socket as tube base pins, good high voltage insulation, and good high frequency characteristics.

Furthermore, such tubes are frequently removed from the sockets, and any means on the socket for providing good electrical contact with 5 the base pins must be able to go through repeated removals and insertions and still maintain the original contact efficiency. For economy in manufacture it is also desirable that a plurality of such-sockets may be readily assembled along a suitable frame.

The socket of my invention satisfactorily fulfills all these requirements.

In the drawing, illustrating a preferred em bodiment of my invention, a socket body preferably of metal, is formed with a rectangular base receiving cylinder 2 and is bent or otherwise shaped to have mounting flanges 4 along two opposite edges. These flanges are adapted to fit over two parallel insulating bars 5 preferably of '20 quartz, isolantite or other suitable refractory insulating material resistant to high'frequency alternating current. The two bars may be extended on either side of the body ,to receive similar bodies in case a plurality of sockets are desired. It is preferable to fix the body to the bars by means of rivet pins 6. I

Fastened to the insulating bars by means of bolts 1 and nuts 9 are four contact brackets l0, one under each corner of the body. These brackets serve to position four contact strips l I which extend symmetrically into the area directly beneath" e opening in the base receiving cylinder 2. It is preferable to fix these contact strips to the brackets by passing the bolts I through the 3.3 strips and applying, and tightening the nuts 9 over them as shown" in Figure 5. It is alsodesirable to insert the strips in a slot I2 in the bracket to prevent rotation. r

The contact strip is formed with a connection lug It on one side of the bolt I, and the opposite free end is folded back on itself and bent to form an outer recess l5 and an inner recess l6. These recesses are substantially cylindrical and vertical. The end of the folded back portion is bent'out slightly to form a directing lip ii.

spread before insertion so that the spring exerts pres'sureand tends to close the inner recess.

It will, therefore, be seen that the gripping function of the inner recess does notdepend on the spring action of the bent back strip, but rather on the spring 22. Consequently the strip may be made of a non-resilient material having good conductivity, and repeated bending of the strip by insertion of the base pins will not deform the strip. as the coil spring 22 will provide the gripping pressure. 7

The inner recesses are positioned below the base aperture to correspond with the positioning of the base pins 25 of a tube base 26, which in this case is that of a standard fifty watt tube. The base is inserted into the socket as far as it will go with the pins adjacent the directing lips H. A slight rotation will cause the pins to enter the inner recesses I6 against the pressure of the spring 22 and snap into place, and as the pins are preferably slightly larger than the normal size of the recesses, a constant and relatively heavy pressure on the contact pins will be continually exerted by the springs. thus providing an excellent, cylindrical gripping contact between the strips and the pins. The tube may be inserted and removed innumerable times without changing the efficiency of the contact, as the coiled spring will not fatigue under such slight movement.

The auxiliary spring not only takes the strain off the fold and prevents the deforming of the fold, but allows a far greater gripping force to be applied to the pin, than if the contact strip alone were to be depended on to supply the gripping pressure.

I have shown no reference mark to determine which contact pin on the base goes in which contact means on the socket, as the reference means used on various tubes are not uniform, the reference mark on some makes being in a different position than in others. As such a specific reference means is no part of my invention, I have omitted it, as means to accomplish this purpose may be easily provided on the socket as described. by anyone skilled in the art.

I claim:

1. In combination with a cylindrical vacuum tube base having contact pins projecting from one end thereof, a socket for said base compriscess, and additional means bearing against the sides of the fold to reinforce the spring action of the fold.

2. In combination with a cylindrical vacuum tube base having contact pins projecting from one end thereof, a socket for said base comprising a plate having a cylindrical aperture adapted to receive said base, a pair of parallel insulating bars attached to said plate, contact strips carried by said bars, each of said contact strips being folded back on itself to form an inner and outer recess, the inner recess being adapted to receive and grip a contact pin when said base is rotated, a spring-retaining pin inserted in said outer recess, a portion of the walls of the outer recess being cut away adjacent the center of said pin, and a coiled spring mounted on said springretaining pin in the cut-away portion of said outer recess, the ends of said spring bearing against the sides of said inner recess to increase the pressure on said contact pin.

RALPH M. HEINTZ. 

